[ARC5] OT? bc-348 bfo question

[Fernando - LU2DFM]

On Fri, Sep 13, 2013 at 07:37:09PM -0400, Jay Coward wrote:
> Check the feedback "gimmick" capacitor. It's a couple of twists of two wires.
> Jay

Thank you; I'm thinking alike. The gimmick looks like original to
me, and it's pretty small: the wire from the BFO coil goes over the
plate wire, but does not coil around it. I think this is too little
coupling.

My feel is that the output of the BFO is too small to get enough carrier
into the detector for moderately strong signals and up. The plate
voltage of the triode section of the 6F7 varies between some 45 to 32
volts as the RF gain is varied (MVC, no AGC position). That's pretty
near what the manual indicates. 

Tomorrow I'll take some meticulous measurements and will decide if more
gimmick capacitance is needed or there's something wrong in the BFO.

Does anyone has a photo of an original gimmick cap? 


-- 
73 de Fer, LU2DFM